1. Field of the Invention
This invention relates to urine specimen collecting means and more particularly to an inexpensive, simple-to-use, disposable device for collecting the mid-stream portion of urine from a female donor.
2. Description of the Prior Art
Urine analysis is a simple and useful tool in diagnosing urinary tract infections which are more common in women. The usefulness of urine analysis for the detection and identification of these infections is lessened by the difficulty in obtaining a specimen which has not been contaminated by the bacteria on, and secretions from, the tissues past which the urine flows before being collected. As urination begins, the flow tends to be weaker. This weaker flow contacts more tissue area and picks up and carries with it more secretions and bacteria. The later, mid-stream flow, exits the body faster and with more force and is therefore fleer of contaminating bacteria and secretions. In addition, the initial, slower, flow serves to "clean" the tissues past which it flows, further causing the mid-stream flow to be less contaminated. Thus, in collecting urine specimens for purposes of diagnosis, it is more advantageous to collect mid-stream urine which is fleer of contaminating bacteria and secretions.
The simplest method for collecting a mid-stream urine specimen is to allow the urine flow to begin, wait a period of time and insert a collecting container into the path of the urine flow. Since it is difficult to stop the flow after it has begun, it is also difficult to catch the mid-stream sample without soiling the hands and the outside of the container. In addition, the individual, herself, must make a judgment as to the correct point at which to place the collector into the flow, thereby introducing anxiety and risk of contamination from errors in judgment by someone who is very likely to be unfamiliar with the procedure. Other means for separating and collecting the mid-stream flow include devices having separate chambers for example, as described in U.S. Pat. No. 3,722,503 whereby the contents of one chamber overflow to a second chamber when a specified volume is attained. In a different arrangement (U.S. Pat. No. 4,569,090), the mouth of a collection bottle protrudes into a larger container. The first portion of the urine is collected in the larger container. When the level of the urine reaches the mouth of the bottle, the urine enters the bottle. These prior art arrangements do not actually provide for the separation of the initial-stream and mid-stream flows. Thus, a portion of the initial flow may be mixed, perhaps because of turbulence, with the mid-stream flow as the level of the urine reaches an overflow level as described in the prior art or as in the case of U.S. Pat. No. 4,569,090 cited above, reaches the mouth of the collection jar.
The patent literature also describes devices, in other context, which employ valve-like devices in urine collection embodiments. The primary purpose of those valves is to prevent spillage after the urine is collected and prior to its being destroyed. For example, U.S. Pat Nos. 3,356,218 and 4,457,314 disclose valve-like devices in two different types of urine collectors. The valve in U.S. Pat. No. 4,457,314 is described as an "anti-back flow mechanism" employed primarily to prevent spillage of the contents. Other U.S. patents that disclose one-way type valves for the purpose of preventing spillage include: U.S. Pat. Nos. 3,928,875; 4,095,124; 4,586,041 and 4,734,154.
Another class of valve urine collectors involve those designed to collect mid-stream urine samples. For example, U.S. Pat. No. 4,494,581 discloses a mid-stream urine collection device which describes, in FIG. 7 thereof, a mechanism in which a floating cork closes a valve after an initial sample of urine has been obtained so that the remaining specimen to be collected will be from the mid-stream.